Submarine sound receiver



June 14, 1927.

1,632,331 H. c. HAYES SUBIARINE SOUND RECEIVER Filed Jan. 2, 1924 gwuantoa:

I atented June 14, 1927.

recur FFICE.

" VEY C. HAYES, OF WASHINGTON, DISTRICT OF COLUMBIA.

SUBMABINE SOUN D RECEIVER.

My invention relates broadly to submarine sound receiving units and more particularly to the mounting of the microphone used therein.

It has been demonstrated that the successful reception of submarine sounds requires some type of receiver that responds more efiiciently to outside sounds which it is desired to hear' than to the numerous local disturbing noises such as are caused by pro- .pellers, engines, auxiliary machinery, shifting cargo, slap ing waves, and the like. It has also been Found that these local noises reach the receiving units, for 'the most part,

through vibrations carried along the ships plating. It has further been found that the intensity of. these disturbing sounds decreases somewhat rapidly in a direction outward perpendicular to the surface of the As a result of these discoveries 1t.

plates.

has been customary to place the receiving units outside the ships skin as great a distance as theprinciples of good construction will permit and to cover them with a blister shaped construction made of thin metal or wood having astreamline form. And to further protectth e receiving units from the I above noises they are again backed by sound screens. But this construction is a very expensive one. a a

7 It is an object of my invention to so mount a receiving unit in a vessels plating that undesirable sounds communicated along the ships sln'n not affect the diaphragm of the microphone, and to provide a unit that is cheap to manufacture and install etficient in operation.

It is a well known principle in sound wave propagation that a portion of the wave energy will be reflected back wherever the medium cdnducting the sound waves changes density or cross-section. The principle of my invention, which I- call a spark plug and ' I type installation depends upon protecting the receiving from the skin vibrations by making that portion of the skin carrying the receiving units much heavier than is the adjacent platin This-results in reflecting back a part of t e skin vibrations when they meet the heavier metal surrounding the receiving'units and ofiers a still further pro- 'tection from'the fact that the part of the vibratory energy that is not reflected back but enters the thick plating will have its amplitude of vibration reduced within the thick plating because the wave front extends to cover the greater cross-section.

The heavy plating not only serves to protect-the region where the receiving' umts" are mounted from the local skin conducted noises but provides a region where the outside sounds can be more sensitively received because the increased inertia of the heavy plating prevents the release of the pressure impulses of the sound waves and thus pre serves the sound energy for energizing the receiving units.

With the above and other objects in view through openings formed in the skin and inertia plate and carries an inertia microphone 4, whichis attached thereto by a threaded stud extending into an interiorly threaded member 15 which is embedded in the body of the diaphragml The diaphragm is the end portion of a rubber housing 16 extending into the vessel in cylindrical form and which is cemented to a reinforcing metal tube 5. This tube with its rubber housing forms a sliding fit into a heavy cylindrical member 8 except for the length occupied by the' diaphragm which is relieved to allow the diaphragm freedom of movement. Watertighimess between the tube 5 and member 8 is secured by a softrubber gasket 9 compressed between rings 10 by means of a threaded ring 11. The inside of the inner ring is welded to the tube 5, as at 17; A cap 12, adjustable upon the member 8, serves as a protection to a cable 6, passing through a watertight sandwich type of packing 7 fiom the microphone chamber, and which" carries the two microphone leads. This cap also holds the tube 5 in place. Afiange 13 forms an integral part of the member 8 or may be a ring welded thereto around the junction 14. The outer face of the diaforming part of this phragm 3 comes flush with the outer surface.

of the inertia plate 2 in order to preserve the streamlining and prevent eddies which always produce receiver noises.

It will be understood that the shape and dimensions of the inertia plate will be dependent upon the number of and spacing between the receiving units employed and also various minor changes. "in details of construction, proportion and arrangement of parts may be made within the scope of the appended claims and without sacrificing any of the advantages of my invention.

Having described my invention, I claim 1. In a sound signal receiver, a body pro-' vided with an opening, a member of relatively high inertia extending from. said opening, a resilient lining within said member, and vibratory responsive means supported by said lining. i

,2. In a sound signal receiver, a body tory responsive means shielded by the memher and by the reinforcement of the opening.

3. In a sound signal receiver, a body structure provided with an opening, reinforcement for said opening of high inertia relative; to the body structure, a member extending from said opening of high inertia relative to the body structure, a resilient lining to said member and vibratory responsive means supported by the lining and shielded by the reinforcement and .the member.

4. In a sound signal receiver, a body structure provided with an opening, a member extending from said opening, a diaphragm supported by but out of direct contact with said member, and a microphone operatively connected to said diaphragm.

5. In a sound signal receiver, a body structure provided with an opening, a member extending from said opening, a diaphragm resiliently supported by but out of direct contact with said member, and a microphone connected to said diaphragm.

HARVEY o. HAYES. 

